Well judging by how Batman has a divekick, a glide, a nice crossup, and those electric bats, I would guess he has good mixups on wakeup at least.
In the lastest CPU Dubai videos posted it shows Superman has a nice wakeup mixup after he ends combos in his airgrab because he could airdash and go for an ambiguous crossup, go for an air laser, or maybe some other option we don't know yet.
So yea, so far I'd have to guess, Batman and Superman. =/